KCNA Practice Test 11 — 15 Questions

Question 1

A Pod has a container that needs to write logs to a file. The administrator wants the logs to persist even if the container restarts. What is the simplest solution?

Accepted Answer

Use an emptyDir volume and mount it at the log path.. An emptyDir volume provides a simple, ephemeral storage solution that persists across container restarts within the same Pod. When a container crashes and is restarted by the kubelet, the emptyDir volume's contents remain intact, allowing log files to survive container restarts without requiring external storage or complex configuration.

Answer

Use a PersistentVolumeClaim for each container.

Answer

Use a hostPath volume to write logs directly to the node filesystem.

Answer

Store logs in a ConfigMap.

Question 2

In distributed tracing, what is a 'span'?

Accepted Answer

A single logical operation within a trace. A span represents a unit of work in a distributed system, often a single operation like an HTTP request or database call.

Answer

A metric measuring request latency

Answer

A collection of related traces

Answer

A log entry with trace context

Question 3

A team wants to manage their Kubernetes infrastructure using code. Which tool is specifically designed for Infrastructure as Code (IaC) and can manage Kubernetes resources?

Accepted Answer

Terraform. Terraform is a dedicated Infrastructure as Code (IaC) tool that uses declarative configuration files (HCL) to provision and manage cloud resources, including Kubernetes clusters and their workloads. It maintains state to track resource dependencies and can orchestrate Kubernetes resources via its Kubernetes provider, making it the correct choice for managing Kubernetes infrastructure as code.

Answer

Helm

Answer

kubectl

Answer

Kustomize

Question 4

You have a Pod that needs to run a one-time batch job to completion. Which resource type should you use?

Accepted Answer

Job. A Job resource is designed for running a finite task to completion, such as a batch job or a one-time computation. Unlike controllers that maintain a desired number of replicas indefinitely, a Job creates one or more Pods and tracks their successful termination. Once the specified number of completions is reached, the Job is considered finished and no further Pods are created.

Answer

StatefulSet

Answer

DaemonSet

Answer

Deployment

Question 5

You need to run a batch job that processes a queue and then terminates. Which Kubernetes resource should you use?

Accepted Answer

Job. A Job is the correct Kubernetes resource for running a batch process that executes a finite task (e.g., processing a queue) and then terminates. Unlike controllers that maintain a desired state indefinitely, a Job creates one or more Pods and ensures they run to successful completion, after which the Job itself completes and no further Pods are created.

Answer

Deployment

Answer

DaemonSet

Answer

StatefulSet

Question 6

Which THREE of the following are valid options for the 'kubectl get' command to display output in different formats?

Accepted Answer

-o wide. `kubectl get -o wide` is a valid output format that displays additional details such as node names and internal IPs for pods, or cluster IPs and ports for services, beyond the default summary columns. This is a standard kubectl output flag for human-readable extended output.

Answer

-o verbose

Answer

--describe

Question 7

Which two of the following are valid ways to expose a Deployment externally to the internet? (Select TWO)

Accepted Answer

Create a Service of type LoadBalancer. A Service of type LoadBalancer provisions an external load balancer (e.g., in cloud environments like AWS, GCP, or Azure) that assigns a public IP or DNS name, making the Deployment directly accessible from the internet. This is a standard method for exposing services externally in Kubernetes.

Answer

Create a Service of type ClusterIP

Answer

Create an Ingress resource

Answer

Create a Headless Service

Question 8

Which Kubernetes control plane component is the primary entry point for all administrative tasks and serves the Kubernetes API?

Accepted Answer

kube-apiserver. The kube-apiserver is the front-end of the Kubernetes control plane and the sole entry point for all administrative operations. It exposes the Kubernetes REST API, validates and processes requests (including authentication, authorization, and admission control), and updates the corresponding objects in etcd. Without the API server, no kubectl command, automation, or internal component communication can occur.

Answer

kube-scheduler

Answer

kube-controller-manager

Answer

etcd

Question 9

An application experiences intermittent failures when calling an external API. Which resilience pattern should be implemented to handle transient faults?

Accepted Answer

Retry. (Retry) is correct because intermittent failures when calling an external API are typically transient faults (e.g., network glitches, temporary service unavailability). The Retry pattern automatically reattempts the failed operation a configured number of times, often with exponential backoff, to overcome these short-lived issues without changing the application's overall architecture. This directly addresses the scenario's requirement to handle transient faults.

Answer

Bulkhead

Answer

Circuit breaker

Answer

Timeout

Question 10

Which component is responsible for aggregating metrics from Kubernetes nodes and exposing them to the metrics API?

Accepted Answer

metrics-server. The metrics-server is the correct component because it is specifically designed to collect resource metrics (CPU and memory) from the kubelet on each node via the Summary API and expose them through the Kubernetes Metrics API. This allows tools like `kubectl top` and the Horizontal Pod Autoscaler to access real-time resource usage without requiring a full monitoring stack.

Answer

Prometheus Server

Answer

Grafana

Answer

Fluentd

Question 11

In a YAML manifest for a Deployment, which field defines the number of pod replicas?

Accepted Answer

spec.replicas. In a Kubernetes Deployment manifest, the `spec.replicas` field is the correct place to define the desired number of pod replicas. This field is a top-level attribute under the Deployment's `spec` object, and the ReplicaSet controller uses this integer value to ensure the specified number of Pods are running at all times.

Answer

spec.strategy.replicas

Answer

metadata.replicas

Answer

spec.template.replicas

Question 12

What is the role of the kubelet on a worker node?

Accepted Answer

It ensures containers are running in a Pod as specified. The kubelet is the primary node agent that runs on every worker node. Its core responsibility is to ensure that containers described in Pod specs (received from the API server via the kube-apiserver) are running and healthy. It does this by interacting with the container runtime (e.g., containerd or CRI-O) to start, stop, and monitor containers, and it reports the Pod and node status back to the control plane.

Answer

It stores cluster state

Answer

It manages network rules for Services

Answer

It runs the container runtime

Question 13

Which Kubernetes component is responsible for maintaining the desired state of the cluster?

Accepted Answer

Deployment controller. The Deployment controller is a core Kubernetes controller that runs as part of the kube-controller-manager. It continuously watches the cluster's current state via the API server and reconciles it with the desired state defined in Deployment objects, ensuring the correct number of Pod replicas are running, updated, and available. This makes it the primary component responsible for maintaining the desired state of the cluster for stateless workloads.

Answer

kube-proxy

Answer

kubelet

Answer

etcd

Question 14

In GitOps with ArgoCD, what does 'self-healing' refer to?

Accepted Answer

Automatically reverting manual changes to match the Git repository. Self-healing automatically reverts any manual changes made to the live cluster state back to the desired state defined in Git, ensuring configuration drift is corrected.

Answer

Automatically scaling applications based on metrics

Answer

Automatically restarting failed pods

Answer

Automatically updating the Git repository when changes are made in the cluster

Question 15

You need to provide an application with configuration data that does not change often and should not be baked into the container image. Which Kubernetes resource should you use?

Accepted Answer

ConfigMap. ConfigMap is the correct Kubernetes resource for providing configuration data that does not change often and should not be baked into the container image. It decouples configuration artifacts from image content, allowing you to update configuration without rebuilding images, and supports injection via environment variables, command-line arguments, or volume mounts.

Answer

Secret

Answer

PersistentVolumeClaim

Answer

ServiceAccount